The present invention relates to vehicle drivetrains, and more particularly to torque converters integrated with starter-generators.
Conventionally, in automotive vehicles with internal combustion engines, starter motors and generators (or alternators) are separate components that are mounted in the engine compartment. The starter is employed only during engine start-up to rotate the engine crankshaft, and the generator (or alternator as the case may be) is used during engine operation to provide electricity for charging the vehicle battery and other vehicle electronics. This arrangement has drawbacks, however, in that the cost is generally high due to the fact that they are separate assemblies that each have their own working components and housings; also, the package space required is not as efficient as possible. This arrangement is particularly inefficient in that the two components rarely, if ever, operate at the same time.
With vehicles becoming smaller and the need to reduce the cost of the vehicles, it is desirable to minimize the cost and packaging space for these two components. This is particularly significant in vehicles that also employ an automatic transmission (or transaxle), and torque converter, because automatic transmission and torque converter overall take up more space than a manual transmission and clutch. As a result, some have attempted to integrate the starter and generator into a single unit. There is a need, however, to accomplish the integration in such a way that the packaging space and cost is minimized while still allowing for both the starter function and the generator function to perform adequately.
Thus, it is desirable to have a vehicle with an internal combustion engine and automatic transmission that overcomes the drawbacks of the conventional arrangement of components. In particular, it is desirable to have a system with an integral starter-generator that mounts compactly with a torque converter assembly, in order to reduce the number of components and the packaging space required in the vehicle""s engine compartment.
In its embodiments, the present invention contemplates an integrated assembly adapted to mount in a vehicle between an engine, having a crankshaft assembly extending therefrom, and a transmission, having a transmission input shaft and stator shaft extending therefrom. The integrated assembly includes a housing adapted to mount between the engine and the transmission. It also includes a torque converter assembly, located within the housing and adapted to mount adjacent to the engine, with the torque converter assembly including a cover adapted to rotatably couple to the crankshaft assembly, and an impeller rotationally coupled to the cover, and with the impeller including an impeller hub adapted to mount about the stator shaft. A motor-generator is located within the housing adjacent to the impeller and adapted to mount between the torque converter assembly and the transmission, with the motor-generator having an ISG stator supported by the housing, an ISG rotor support mounted and rotatable relative to the housing, and with an ISG rotor mounted on the ISG rotor support adjacent to the ISG stator, and at least one flexible member connected between the ISG rotor support and the impeller such that the ISG rotor is rotationally coupled to the impeller.
The present invention further contemplates an integrated assembly adapted to mount in a vehicle between an engine, having a crankshaft assembly extending therefrom, and a transmission, having a transmission input shaft and stator shaft extending therefrom. The integrated assembly includes a housing adapted to mount between the engine and the transmission; and a torque converter assembly, located within the housing and adapted to mount adjacent to the engine, with the torque converter assembly including a cover adapted to rotatably couple to the crankshaft assembly, and an impeller rotationally coupled to the cover, and with the impeller including an impeller hub adapted to mount about the stator shaft. The integrated assembly also includes a bearing mounted between the impeller hub and the housing; and a motor-generator, located within the housing adjacent to the impeller and adapted to mount between the torque converter assembly and the transmission, with the motor-generator having an ISG stator supported by the housing, an ISG rotor support riding on a bearing mounted to the housing, and with an ISG rotor mounted on the ISG rotor support adjacent to the ISG stator, and a set of compliant pin assemblies connected between the ISG rotor support and the impeller such that the ISG rotor is rotationally coupled to the impeller.
The present invention also contemplates an integrated assembly adapted to mount in a vehicle between an engine, having a crankshaft assembly extending therefrom, and a transmission, having a transmission input shaft and stator shaft extending therefrom. The integrated assembly has a housing adapted to mount between the engine and the transmission; and a torque converter assembly, located within the housing and adapted to mount adjacent to the engine, with the torque converter assembly including a cover adapted to rotatably couple to the crankshaft assembly, and an impeller rotationally coupled to the cover, and with the impeller including an impeller hub adapted to mount about the stator shaft. The integrated assembly additionally has a motor-generator, located within the housing adjacent to the impeller and adapted to mount between the torque converter assembly and the transmission, with the motor-generator having an ISG stator supported by the housing, an ISG rotor support riding on ISG bearings mounted to the housing, with the impeller hub supported by the ISG rotor support, an ISG rotor mounted on the ISG rotor support adjacent to the ISG stator, and a rotationally rigid, axially flexible member connected between the ISG rotor support and the impeller such that the ISG rotor is rotationally coupled to the impeller; and a bearing mounted between the ISG rotor support and the housing.
An embodiment of the present invention allows for an integrated assembly that includes both a torque converter assembly and an integrated starter-generator assembly which mounts between an engine and a transmission.
An advantage of the present invention is that the packaging space required to include an ISG in an engine compartment of a vehicle is minimized.
Another advantage of the present invention is that a separate starter and generator are not required, reducing the cost of the overall assembly.